Browsing by Author "Vital, Helio C."
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Item Open Access Cost-effective approach to lung cancer risk for a radiological dispersal device (RDD) scenario(De Gruyter Open, 2019-12-11) Costa, Karolina P. S.; Lima, Sergio X.; Brum, Tercio; Lima, Zelmo R.; Amorim, Jose C. C.; Healy, Matthew J. F.; Vital, Helio C.; Prah, Matjaž; Andrade, Edson R.A release of radioactive material into the environment can lead to hazardous exposure of the population and serious future concerns about health issues such as an increased incidence of cancer. In this context, a practical methodology capable of providing useful basic information from the scenario can be valuable for immediate decisions and future risk assessment. For this work, the simulation of a radiological dispersal device (RDD) filled with americium-241 was considered. The radiation dose simulated by the HotSpot code was used as an input to the epidemiological equations from BEIR V producing the data used to assess the risk of lung cancer development. The methodology could be useful in providing training for responders aimed to the initial support addressed to decision-making for emergency response at the early phase of an RDD scenario. The results from the simulation allow estimating (a) the size of the potentially affected population, (b) the type of protection action considering gender and location of the individuals, (c) the absorbed doses, (d) the matrix of lung cancer incidence predictions over a period of 5 years, and (e) the cost-effectiveness in the initial decision environment.Item Open Access Potential contribution of selected metallic restorative dentistry materials to X-ray fluorescence(Cambridge University Press, 2019-06-17) Andrade, Edson R.; Oliveira, Ana Lucia N.; Funcke, Luisa N.; Souza, Leonardo Henrique F. F.; Healy, Matthew J. F.; Vital, Helio C.Recent advances have led to the use of new materials in dental restoration which is an area of rapid growth. Applications include improving oral aesthetics and essential rehabilitation, whilst procedures range from the recovery of partial elements (inlays) to fitting dental implants. Ceramics, polymers and metallic materials have all been successfully employed in dental applications and benefit from new cost efficient manufacturing techniques. The application of radiographic techniques in dentistry and other medicine is also increasing, and the combination of new materials and radiation can lead to an elevated health risk. X-rays can interact with metallic materials producing X-ray fluorescence, which can increase the radiation dose in proximity to restorative material and increase the risk of live biological tissue becoming cancerous. The issue demands consideration so that the biological risks associated with such procedures are kept as low as possible. Comparisons of doses calculated for several materials have provided evidence that the Ti cp and NiCrTi alloys present less contribution to the increase of dose in surrounding soft tissue and the potential deleterious biological effects. On the other hand, Amalgam appears to be the most deleterious alloy.Item Open Access Radiological risk assessment by convergence methodology model in RDD scenarios(Wiley, 2016-02-19) Rother, Fagner C.; Rebello, Wilson F.; Healy, Matthew J. F.; Silva, Mauricio M.; Cabral, Paulo A. M.; Vital, Helio C.; Andrade, Edson R.A radiological dispersal device (RDD) is a simple weapon capable of causing human harm, environmental contamination, disruption, area denial, and economic cost. It can affect small, large, or long areas depending on atmospheric stability. The risk of developing a radio-induced cancer depends on exposure, and an effective response depends upon available timely guidance. This article proposes and demonstrates a convergence of three different capabilities to assess risk and support rapid safe resource efficient response. The three capabilities that are integrated are Hotspot for dispersion, RERF for epidemiological risk, and RESRAD-RDD for response guidance. The combined methodology supports decisions on risk reduction and resource allocation through work schedules, the designation and composition of response teams, and siting for operations. In the illustrative RDD scenario, the contamination area for sheltering, evacuation, and long-term public concern was greatest for calm atmospheric conditions, whilst close-quarter responders faced highest dose rates for neutral atmospheric conditions. Generally, the risks to women responders were found to be significantly greater than for men, and the risks to 20-year-old responders were three times that of their 60-year-old counterparts for similar exposure.Item Open Access Simulated nuclear contamination scenario, solid cancer risk assessment, and support to decision(De Gruyter Open, 2019-04-01) Lima, Sergio X.; Costa, Karolina P. S.; Lima, Zelmo R.; Rother, Fagner C.; Araujo, Olga M. O.; Vital, Helio C.; Brum, Tercio; Wilson, F.R.S; Amorim, Jose Carlos C.; Healy, Matthew J. F.; Andrade, Edson R.The detonation of an (hypothetical) improvised nuclear device (IND) can generate atmospheric release of radioactive material in the form of particles and dust that ultimately contaminate the soil. In this study, the detonation of an IND in an urban area was simulated, and its effects on humans were determined. The risk of solid caner development due to radiation was calculated by taking into account prompt radiation and whole-body exposure of individuals near the detonation site up to 10 km. The excess relative risk (ERR) of developing solid cancer was evaluated by using the mathematical relationship from the Radiation Effects Research Foundation (RERF) studies and those from the HotSpot code. The methodology consists of using output data obtained from simulations performed with the HotSpot health physics code plugging in such numbers into a specific given equations used by RERF to evaluate the resulting impact. Such a preliminary procedure is expected to facilitate the decision-making process significantly.